1. Field of the Invention
The invention relates to a foldable frame of a playpen, especially to a foldable frame which can be simply and quickly folded up and has a relatively small folded volume.
2. Description of Related Art
Playpens are favored by many parents as they can provide a safe place for a baby to rest or play.
The foldability of playpens is important because:
1. the small folded volume will be convenient for a family to store and transport it;
2. the small folded volume will also bring convenience in packing and transportation for manufacturers.
Nearly all recently developed foldable playpens have a frame made of metal poles which are connected by joints. The poles can rotate with respect to the joints to make the whole frame foldable. For example, a typical such kind of playpen has a central controlling joint at the center of the bottom of the frame, and locking joints at the middle of each of four supporting upright poles. When it is necessary to fold the playpen, the above five joints must all be released first and then the central controlling joint may be pulled upward to make the four supporting upright poles move towards the central joint.
However this kind of foldable playpen has certain drawbacks. For example, to fold the bed, a user has to release five joints, especially one on the bottom of the frame: whereby it is necessary to bend down and go round the bed at least once.